Electrical cable harness and assembly for transmitting ac electrical power

ABSTRACT

An electrical connector/cable harness includes an electrically insulative housing and first and second passageways extending from a first end of the connector/cable harness to a second end thereof, first and second electrically conductive wires disposed in the passageways, respectively, wherein the passageways and the wires therein reverse their dispositions in the connector/cable harness such that at the second end of the connector/cable harness the two wires are disposed oppositely to their disposition at the first end of the connector/cable harness.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from U.S. Provisional PatentApplication No. 61/072,226, filed Mar. 28, 2008 in the names of Ruel D.Little and Zachary A. King.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to assemblies for interconnecting AC generatorsand AC powered systems, and for converting solar energy to AC electricalpower, and to electrical connector and cable harness means forinterconnecting components of such assemblies.

2. Description of the Prior Art

Assemblies for converting DC sources of electrical energy, such as solarcells, batteries, and the like, to readily usable AC electrical powerare known. However, current systems, particularly in the solar energyarea, comprise a variety of components from multiple manufacturers. Suchcomponents in the solar energy area include photovoltaic cells, commonlyreferred to as solar cells, which convert solar energy to DC electricalpower. Such cells are generally grouped in supporting and protectivephotovoltaic modules which are customarily mounted on roof tops, orother such structures, exposed to sunlight. The photovoltaic cells, andtherefore, the photovoltaic modules, produce DC electrical power.

Usually, a number of photovoltaic modules are connected to an inverterwhich converts DC power output of the photovoltaic modules to AC power.

Photovoltaic systems usually include multiple DC photovoltaic modulesconnected in one or more series, or strings, feeding an inverter, whichconverts DC power to AC power. This system suffers from inefficiencies,such as module-to-module mismatch and power loss due to varying moduleorientations and significant shading losses. To connect one or morephotovoltaic modules together to form a module string, there is provideda module cable harness including transmission wires and connectorportions. A plurality of module and inverter strings may be connected toan AC buss by a module cable harness. The AC module buss may beconnected to a junction box by a further cable harness with appropriateconnector means.

The above described building blocks for photovoltaic power generatingsystems thus include DC generating photovoltaic modules, DC to ACinverters, DC and AC switches and other mechanical and electricalcomponents.

Past AC modules have connected to a utility grid by utilization of an ACmodule cable harness which links AC module to AC module, functioning asboth an AC physical string and an AC electrical buss.

The bussing of AC modules onto an AC power buss maintains the same ACvoltage while it incrementally increases current with each AC moduleadded. One or more strings/busses of AC modules are then connected to acombiner junction box to transition from the AC module cable harness toa runback wire to the service panel. The combiner junction box providesa terminal for transitioning the combined busses to a larger wire gaugeand, optionally, overcurrent protection for each of the two AC busses.

The current state of the art for an AC module cable harness uses two,three-wire, quick connectors in the form of a male and female part and athree-wire cable connecting them. A single phase 120 volt AC modulemicro-inverter connects to the three-wire cable to make up the AC modulebuss. The micro inverter connects to line, neutral, and ground on the ACmodule buss.

In the current state of the art for two AC module strings connected to acombiner junction box, the two strings each are an AC module buss with amaximum of n modules. A standard AC module with a straight-through ACmodule cable harness connects to a combiner junction box in the centerof two AC module strings of n modules.

AC modules must operate at the voltage of the grid to which they areinterconnected. Typical USA residential and commercial grid serviceshave available single-phase 120V, three-phase 120/208V, or split-phase120/240V AC. It is desirable to have a product is operable on a 120V ACsingle phase line, because it is a universally available servicevoltage. In a residence, there is typically a split-phase 120/240V ACservice available, consisting of two line conductors and a singleneutral. The voltage between line and neutral is 120V AC. For typicalcommercial settings there is a three-phase 120/208V AC service thatconsists of three lines and a neutral. In this case, the voltage betweena line and neutral is also 120V AC.

It also is desirable to connect as many AC modules on a single AC modulestring as possible, thereby avoiding additional junction boxes andservice panel runback wires. In addition to adding cost, the junctionbox may require a roof penetration or may require a visible metal cladconduit, which installers try to minimize because of roof warrantyissues and aesthetics.

The maximum number of AC modules on a buss depends on the AC modulecurrent rating, wire gauge and wire temperature rating. Highertemperature ratings and larger wire gauge increase the cost of the ACmodule cable harness. Therefore, as n increases, the cost of the ACmodule cable harness increases.

A limitation of the current AC module physical layout is that thejunction box must be placed in a physical location that assures that itwill accommodate the desired physical layout and electrical requirementsof the AC module string.

SUMMARY OF THE INVENTION

An object of the invention is to provide an electrical connector whichmay be disposed as a component of an assembly for converting solarenergy to AC electrical power, and/or in a cable harness or system bywhich AC components are connected to each other.

A further object of the invention is to provide an electrical cableharness for interconnecting an AC power source, such as a DCphotovoltaic module and inverter, or a battery and inverter, or a windor water turbine AC generator, to an AC power assembly.

A still further object of the invention is to provide a power generatingassembly including a plurality of the aforesaid AC modules incommunication with a junction box, and a line-alternating cable harnessassembly which facilitates the communication.

A still further object of the invention is to provide the aforesaidpower generating assembly wherein selected components of the powergenerating assembly and the cable harness assembly and the junction boxare provided with connector means configured to physically engage andinterlock with complementary connector means, the connector means beingconfigured so as not to engage with each other unless properly paired,such that such connectors, and thereby the other components of thesystem, cannot be inappropriately interconnected. Any of theconnecter/cable harness devices provided herein can be paired with anyother like connector/cable harness and effect a correct connection for abuss.

The above and other objects and features of the invention, includingvarious novel details of construction and combinations of parts, willnow be more particularly described with reference to the accompanyingdrawings and pointed out in the claims. It will be understood that theparticular device embodying the invention is shown by way ofillustration only and not as a limitation of the invention. Theprinciples and features of this invention may be employed in various andnumerous embodiments without departing from the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference is made to the accompanying drawings in which are shownillustrative embodiments of the invention, from which its novel featuresand advantages will be apparent.

In the drawings:

FIG. 1 is a diagrammatic sectional view of a cable harness housinghaving passageways extending therethrough, and electrically conductivewires disposed in the passageways;

FIG. 1A is a diagrammatic sectional view similar to FIG. 1, but showingan additional passageway and electrically conductive wire extendingtherethrough;

FIG. 1B is a wiring schematic of the embodiment of FIG. 1A, showingconnector means by which cable harnesses may be interconnected;

FIG. 1C is similar to FIG. 1A, but showing a further passageway andelectrically conductive wire extending therethrough;

FIG. 2 is a perspective view of first and second cable harness connectormeans illustrative of a keying arrangement of connector contacts;

FIGS. 3A-3D show diagrammatically four configurations of connectorswhich have keying contacts insuring proper interconnection of connectormeans of cable harnesses;

FIG. 4 is a schematic view of a prior art discrete DC photovoltaicmodule in communication with a discrete inverter which is incommunication with a cable harness;

FIG. 5 is a schematic view of a photovoltaic module with a dedicatedinverter, to form an AC module, shown in combination with an AC cableharness, as shown in FIG. 1B;

FIG. 6 is a schematic view of a string of AC modules in combination withcable harnesses, and in further cooperative combination with a junctionbox;

FIG. 7 is a schematic view of a plurality of strings of AC modules incombination with cable harnesses and a junction box;

FIG. 8 is a schematic view of AC modules connected to one another byalternating line cable harnesses and by an extension cable;

FIG. 9 is a schematic view of multiple strings of AC modules incombination with cable harnesses and junction boxes; and

FIG. 10 is a schematic view of a string of AC modules and a five linealternating cable harness.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, it will be seen that an electrical cable harness 8,suitable for interconnection of components of an assembly for convertingsolar power to AC electrical power, includes an electrically insulativehousing 10 having first and second ends 12, 14. A plurality ofpassageways 16, 18 extend through the housing 10 from the first end 12of the housing 10 to the second end 14 of the housing 10.

The first passageway 16, between the first and second connector ends 12,14 of the housing 10, is provided with a first angled portion 20extending to a portion 22 of the first passageway 16 in alignment withthe second passageway 18 and extending to the second end 14 of thehousing 10.

Similarly, the second passageway 18, between the first and second ends12, 14 of the housing 10, is provided with a second angled portion 24extending to a portion 26 of the second passageway 18 in alignment withthe first passageway 16 and extending to the second end 14 of thehousing 10.

A plurality of electrically conductive elongated bodies 30, 32 aredisposed, respectively, in the plurality of passageways 16, 18 andextend through the housing 10 from the first end 12 of the housing 10 tothe second end 14 of the housing 10, the electrically conductive bodiescomprising at least the first and second electrically conductive bodies30, 32.

Thus, at the second end 14 of the housing 10, the first and secondpassageways 16, 18 and therefore the first and second electricallyconductive bodies 30, 32, are reversed in their positions relative totheir dispositions at the first end 12 of the housing 10.

The electrically conductive bodies 30, 32 commonly comprise wires andmay comprise a first line wire 34 and a second line wire 36,respectively.

Referring to FIG. 1A, it will be seen that the plurality of passagewaysand electrically conductive elongated bodies which extend through thehousing 10 may include a third passageway 17, through which extends aneutral wire 38. The passageway 17 and neutral wire 38 extend throughthe housing 10 from end 12 to end 14 so as to occupy the same positionat the second end 14 of the housing 10 as it does at the first end 12 ofthe housing.

Similarly, and referring to FIG. 1C, it will be seen that the pluralityof electrically conductive bodies which extend through the housing 10may include a fourth passageway 19 in which there is disposed a groundwire 44. The passageway 19 and the ground wire 44 extend through thehousing 10 from end 12 to end 14 so as to occupy the same position atthe second end of 14 of the housing 10 as it does at the first end 12 ofthe housing.

As shown schematically in FIG. 1B, assuming that an AC power source isconnected to the line wire 34 and neutral wire 38 of a connector means28 of a cable harness 8, the pass-through wire 46 is not energized. Thesecond connector means 8′ is also connected to the line wire 34′ andneutral wire 38′ of an AC power source, and a pass-through wire 46′ isnot energized. When the connectors 28 are mated, the energized line 34of the cable harness 8 mates to the pass-through wire 46′ of the cableharness 8′. The opposite is true for the cable harness 8′, its line wire34′ connecting to the pass-through wire 46 of cable harness 8.

As a result, two separate lines are created automatically, with a sharedneutral wire, such that every other AC power source will be on the sameline wire and adjacent AC power sources will be on the other line wire.

Each of the cable harness connector means is readily connectable to anidentical connector means.

Referring to FIGS. 2 and 3A-3D, it will be seen that the housings 10 maybe provided with electrically conductive male pins 40 and electricallyconductive female pins 42 mounted thereon and connected to the wires 34,36, 38 and 44 in known fashion. The pins 40, 42 are arranged such thatcable harness connector means 28 are connectable to each other in onlyone orientation.

In FIGS. 3B, 3C and 3D there are depicted other connector pinarrangements for three wire connectors, including for example,combinations of first and second line wires 34, 36, neutral 38 andground 44 wires.

The connector pins 40, 42 are disposed on the connectors 8, 8′ bygender, location and conductor designations, such as line wires 34, 36,which serve also as pass-through wires, as will be discussedhereinbelow, a neutral wire 38 and, optionally, a ground wire 44. Theconductor pins 40, 42 of each cable harness connector 8, 8′ are disposedsymmetrically about two symmetry axes. In FIGS. 3A-3D, the firstsymmetry axis a-a is depicted by horizontal dashed lines and the secondsymmetry axis b-b by vertical dashed lines. Circles denote femaleconductor pins; circles with center dots denote male conductor pins.

The connector 28 is symmetrical about the first symmetry axis a-a whichdoes not intersect any conductor pin 40, 42. The symmetry includes threeattributes: location, gender (male, female) and designation (line,neutral, ground). A conductor pin 40 location is mirrored across theaxis line a-a by a pin 42 of the opposite gender and of the samedesignation (i.e., line, neutral, ground).

The connector 28 is symmetrical about the second symmetry axis b-b,which is perpendicular to the first symmetry axis a-a, and which bisectsline conductor pins 40, 42. A conductor pin 40, 42 location is mirroredacross the second symmetry axis b-b by a pin 40, 42, wherein genders areopposites and designations are common.

The aforesaid symmetry insures that a connector 28 is physically able tomate to an identical connector that is rotated 180 degrees, and insuresthat conductors of proper designation are electrically connected.

A hermaphroditic “pin”, as illustrated schematically in FIG. 1B, wherethe neutral wire connector pins 52, 521 are both male and female, may beused, but the symmetries still prevail.

Referring to FIG. 4, it will be seen that customarily in the prior art,photovoltaic modules 47 (solar cells) are adapted for conversion ofsolar energy S to electrical power, more specifically direct current(DC). Inasmuch as usable power in households, businesses, and the like,is alternating current (AC), all such modules must be connected to aninverter 48 which converts DC energy to AC energy. Typically, a numberof the solar cells 47 are in communication with an inverter 48. Thus, inplanning roof-top dispositions of solar cells and inverters, they mustbe organized such that an appropriate number and disposition ofinverters is allowed for an appropriate number and disposition of solarcells.

Referring to FIG. 5, it will be seen that in accordance with the presentinvention, each photovoltaic module 50 includes a dedicated inverter 48,enabling any number and disposition of photovoltaic modules 50 where theinverters are physically matched with the locations of modules. Suchcombinations of modules and inverters are herein referred to as “ACmodules” 50.

The AC module 50 is adapted for connection to a cable harness which maybe provided with the wiring and cross-over feature illustrated in FIG.1B. That is, the cross-over feature may be present in a cable harness,such that in the cable 8, the line wires 34 and 36 reverse relativepositions as they pass through the cable harness.

Referring still to FIG. 5, it will be seen that in an AC module cableharness 8 provided with a line wire 34, a neutral wire 38, a second linewire 36 serving as a “pass-through” wire and, optionally, an earthground wire 44, the electrical path for line wire 34 is switched withthe pass-through wire 36. The cable harness 8 also is provided withmeans to connect the cable harness to the AC output (electrical line L,neutral N, and ground G) of an AC module 50.

Referring to FIG. 6, there are shown a plurality of AC modules 50 a, 50b, and 50 c connected to a junction box 70. A ground wire 44, a neutralwire 38, and two line wires 34, 36 interconnect the junction box 70 anda selected number of AC modules 50 a, 50 b, and 50 c, and any additionalAC modules desired. The ground wire 44 and neutral wire 38 are incommunication with each of the modules 50 a, 50 b, and 50 c, etc.However, the connector means 8, 8′ insure that only line wire 36connects with modules 50 a and 50 c, and line wire 34 connects with theAC module 50 b. That is, every other AC module connects with line wire34 and each AC module therebetween connects with line wire 36. Thus,each line wire 34, 36 at every other module becomes a pass-through wire,such that each line wire services one-half of the modules 50 in a stringof modules.

Thus, twice as many AC modules can be connected together withoutexceeding the wire current carrying limit of the cable harnesses andrelated wiring. The AC module string requires only a standard junctionbox that can be located at an end of the string.

The line-alternating feature assures that approximately half the ACmodules 50 are supplying current to one line 34 in the cable harness 8and the current from the other half of the AC modules is suppliedcurrent to the other line wire 36. Current is therefore balanced betweenthe two AC lines 34, 36, unless there is an odd number of AC modules 50.In the case of an odd number of AC modules, there is a small currentimbalance between the two lines 34, 36. However, the maximum amount ofthe imbalance is no greater than the current limit of one AC module. Inaddition, the current traveling on the neutral wire 38 is defined as thecurrent imbalance, and therefore will be no greater than the currentlimit of one AC module. There is thus provided a line-alternatingharness 8 that insures that current on its two lines 34, 36 is balancedto within the current limit of one AC module. The current on each line34, 36 of the line-alternating cable harness 8 is thus evenly balancedwithout special action required by an installer, and the maximum currenton the neutral wire 38 is the current limit of one AC module.Accordingly, the current on the neutral wire is minimized.

A feature of the line-alternating cable harness 8 is that in any twoneighboring AC modules 50 a, 50 b connected to each other (FIG. 6) via aline-alternating cable harness 8, one of the modules will be connectedto the line wire 34, and the other module will be connected to the linewire 36. An advantage of the line-alternating cable harness is that eachAC module 50 can be manufactured, including the line-alternating cableharness 8, identically, while still maintaining the alternating patternwhen connected together.

Thus, in a string of 2 n AC modules 50 a, 50 b, etc., n of the moduleswill be connected to a first line, and n of the modules will beconnected to a second line. When the line-alternating cable harnessconnects to a junction box 70 (FIG. 6), the line wire and pass-throughwire are both 120V AC buss lines relative to the neutral line 38. Thejunction box 70 receives the two line wires 34, 36, neutral wire 38, andoptionally a ground wire 44, and transitions directly to a 120/240V ACor 120/208V AC service. The junction box 70 can therefore accept two ormore 120V AC module busses, with no need for overcurrent protection ortransitioning to a larger gauge wire to a utility power service. Becauseeach line in the line-alternating cable harness 8 can electrically carrythe current for n AC modules, the total length of the AC module stringcan be 2n AC modules (FIG. 6).

A line-alternating cable harness that uses two line wires insures thateach AC module added to an AC module string is connected to the oppositeline from the previous AC module in the string, regardless of where thebuss junction box is located or the presence of an extension cable inthe string. Installers do not need specialized knowledge for connectingAC modules together in a string, or locating the junction box, therebysimplifying installations, reducing the cost and increasing the qualityof installation.

The AC module 50 with a 120V AC output and a line-alternating cableharness can connect to either a 120/240V AC or a 120/208V AC standardjunction box 70 at either end of the AC module string of up to 2n ACmodules.

If a further connector is added to the standard junction box to create abuss junction box, then the junction box can be located at either end ofthe AC module string or at any location in between any two AC modules 50a, 50 b, 50 c, 50 d, 50 e (FIG. 7). The buss junction box 70 passes thebuss through, as at 72, thereby maintaining the alternating pattern ofthe two lines 34, 36. An installer need not keep track of how many ACmodules are on a particular line, as the modules will be evenly balancedbetween both lines.

An AC module 50 and a line-alternating cable harness 8 is adapted toconnect to a 240V AC or 208V AC (wye) buss junction box 70 at anyposition along the AC module string of up to 2n modules (FIG. 7), thushaving the flexibility to position a new buss junction box anywhere inthe AC module string. Overcurrent protection and transitioning to largerwire size are unnecessary.

In addition to a junction box inserted between two AC module strings, itis sometimes necessary to extend an AC module cable harness to connectto an AC module that is not physically nearby. This may occur, forexample, if an AC module string must avoid an obstacle on a roof, orwhen one AC module string needs to connect to another row or column ofAC modules.

An extension cable 62 (FIG. 8) for a line-alternating cable harness 8consists of a cable with a connector means 28 at each end. Electrically,the extension cable 62 functions as a pass-through. That is, no linewires are crossed from the first connector means 28 to the secondconnector means 281 in the extension cable 62.

The benefit of the line alternating cable harness and junction boxapplies to a 208V AC -wye service connection, as well as a 240 voltservice. The junction box 70, with 2n AC modules, may be connected totwo of the three wires 34, 36, 44, as well as neutral wire 38 at, aservice panel.

In FIG. 9 there is shown a three-phase 120/208V AC service, with threeseparate AC module busses 80, each comprising 2n AC modules 50. Theline-alternating wiring harness 8 creates two 120V AC lines in each ofthree junction boxes 70. The output of each junction box 70 is then twolines 34, 36 and a neutral line 38. When each junction box connects totwo separate legs of the three-phase service, a balanced connection ismade with two 120 V AC module lines connected to each 120V leg of thethree-phase service.

This benefit allows maximization of the current carrying capacity of arunback wire to a 208V AC service panel from three separated AC modulestrings 80 with 2 n modules amounting to 6 n AC modules. This isachieved by fully balancing the three AC lines using three buss or endjunction boxes 70 from the AC module strings 80; one connected toservice lines A and B, another to B and C and the third to C and A (FIG.9).

Another embodiment of the three phase 208V AC configuration is athree-line, line-alternating harness shown in FIG. 10. In each cableharness 8, there are two line wires 34, 36 and a third line wire 39which crosses over the line wires 34, 36. This embodiment creates apattern that alternates the three active lines 34, 36, 39 over threesequential AC modules 50, 50 a, 50 b and then repeats. A total of 3n ACmodules may be in a string that transitions to a buss junction box 70.The junction box will then transition to a four-wire runback (includingground) that connects to three-wire 208V AC.

Thus, there is provided a line-alternating harness 8 that includes threeline wires, 34, 36, 39 in an alternating pattern to create three 120V ACline outputs for use with a 208V AC-wye service. The current on eachline of the 208VAC-wye service is evenly balanced within the outputvalue of one AC module.

Accordingly, AC modules 50, 50 a, 50 b, etc., can be connected to oneanother with no consideration by an installer for connector means“gender”. Furthermore, the combination creates a foolproof wiring methodwhere the connection between an AC module 50, 50 a, 50 b and a junctionbox 70, or an AC module and an extension cable 62, will not break thepattern of the alternating lines. An installer, therefore, cannot createa hazardous connection along the AC buss or unbalance the AC buss. An ACmodule harness 8 is adapted to connect two or more AC modules in a rowwhile maintaining the line-alternating feature.

While the cable harness/connector arrangement has been describedhereinabove in conjunction with AC photovoltaic modules, it will beappreciated that the cable harness/connector is useful in conjunctionwith AC generators, such as wind and water turbines, andbattery-inverter combinations.

It will be understood that many additional changes in the details,materials, steps and arrangements of parts, which have been hereindescribed and illustrated in order to explain the nature of theinvention, may be made by those skilled in the art within the principlesand scope of the invention as expressed in the appended claims.

1. An electrical cable harness comprising an electrically insulativehousing and first and second passageways extending from a first end ofthe housing to a second end thereof, first and second electricallyconductive wires disposed in said passageways, respectively, whereinsaid passageways and said wires therein reverse their dispositions inthe housing such that at the second end of the housing said first andsecond wires are disposed oppositely to their disposition at the firstend of the housing.
 2. An electrical cable harness comprising: anelectrically insulative housing having first and second ends; aplurality of passageways extending through said housing from the firstend of said housing to the second end of said housing, said plurality ofpassageways including first and second passageways; said firstpassageway between said first and second ends of said housing having afirst angled portion extending to a portion of said first passageway inalignment with said second passageway and extending to the second end ofsaid housing; and said second passageway between said first and secondends of said housing having a second angled portion extending to aportion of said second passageway in alignment with said firstpassageway and extending to the second end of said housing; a pluralityof electrically conductive elongated bodies disposed in said pluralityof passageways and extending through said housing from said first end ofsaid housing to said second end of said housing, said plurality ofelectrically conductive bodies including first and second electricallyconductive bodies; said first electrically conductive body beingdisposed in said first passageway and said second electricallyconductive body being disposed in said second passageway proximate thefirst end of said housing; wherein at said second end of said housingsaid first and second passageways and said first and second electricallyconductive bodies are reversed in their positions relative to theirdispositions at the first end of said housing.
 3. The cable harness inaccordance with claim 2 wherein said plurality of electricallyconductive bodies comprise wires, said first electrically conductivebody comprising a line wire and said second electrically conductive bodycomprising a pass-through wire.
 4. The cable harness in accordance withclaim 3 wherein said plurality of passageways further comprises a thirdpassageway and a third electrically conductive body of said plurality ofelectrically conductive bodies comprises a neutral wire disposed in saidthird passageway.
 5. The cable harness in accordance with claim 4wherein said plurality of passageways further comprises a fourthpassageway and a fourth electrically conductive body of said pluralityof electrical conductive bodies comprises a ground wire disposed in saidfourth passageway.
 6. The cable harness in accordance with claim 3wherein each of said wires is connected to one of a first line pinextending from said housing and a receptacle disposed in said housing,said receptacle being adapted to receive a second line pin duplicativeof said first line pin, such that said cable harness is provided withconnector means at either end thereof which is connectable to either endof a second cable harness of substantially identical structure.
 7. Thecable harness in accordance with claim 6 wherein said housing connectormeans is symmetrical about a first center axis that is removed from saidfirst line pin and is symmetrical about a second center axisperpendicular to the first center axis and which bisects the first linepin, and a location of said first line pin is mirrored across the secondcenter axis, the symmetries rendering said connector means physicallyadapted to mate with said substantially identical second connectorhousing rotated 180° relative to said first connector.
 8. An electricalconnector assembly, the assembly comprising a first connector housinghaving a plurality of connector male and female pins on a face thereof,and a second connector housing having a plurality of male and femalepins on a face thereof, the connector housings each being adapted fordisposition such that the male pins are received by the female pins inconnecting the first connector housing to the second connector housing;wherein in each connector housing the pins are disposed symmetricallyabout a first symmetry axis, which first symmetry axis does notintersect any connector pin, the pins on a first side of the firstsymmetry axis being mirrored across the first symmetry axis by the pinson a second side of the first symmetry axis; and wherein in eachconnector housing the pins are disposed symmetrically about a secondsymmetry axis, which second symmetry axis bisects conductor pins and isperpendicular to the first symmetry axis, the conductor pins on a firstside of the second symmetry axis being mirrored across the secondsymmetry axis by the pins on a second side of the second symmetry axis;such that said first and second connector housings are adapted toreceive each other and interconnect when the first connector housing isdisposed 180 degrees relative to the second connector housing.
 9. An ACmodule assembly comprising: a first AC module for converting solarenergy into AC electrical power, the module comprising at least onephotovoltaic cell adapted to receive solar radiation and generate a DCelectrical power output, and an inverter for converting the DCelectrical power output to AC electrical power; a cable harness inelectrical communication with at least line and neutral electricallyconductive wires of said AC module and having at a first portion thereofa first connector means having electrically conductive contacts mountedthereon and in communication with at least line, neutral, andpass-through electrically conductive wires extending through said cableharness, and at a second portion thereof a second connector means havingelectrically conductive contacts mounted thereon and in communicationwith the line, neutral, and pass-through electrically conductive wiresextending through said cable harness; wherein in said cable harness theline wire and the pass-through wires are physically reversed in theirpositions; whereby said cable harness provides for line-alternatingcable connection between said first AC module and a second AC module,such that said first AC module line wire is connected to thepass-through wire of the second AC module, and the first AC modulepass-through wire is connected to the second AC module line wire. 10.The AC module assembly in accordance with claim 9 wherein said connectormeans and cable harness are further provided with ground wires extendingserially therethrough.
 11. The AC module assembly in accordance withclaim 9 wherein a selected number of further AC modules is connectableto said AC module assembly to provide an extended AC module string. 12.The AC module string in accordance with claim 11 wherein said AC modulestring is further provided with a junction box adapted to connectivelyreceive at least one of said cable harnesses.
 13. A cable harness forconnection to an AC power source, the cable harness having a pluralityof electrically conductive wires extending therethrough, said wirescomprising at least first and second line wires separated from eachother along the length thereof and adapted for connection to wiresextending from the power source, wherein said first and second linewires are reversed in their positions in the cable harness, such that insuccessive cable harnesses connected to each other and each connected toa discrete power source, the first line wire in a first harness isconnected to the electrical output of the first of the power sources,and the second line wire is not connected to the electrical output ofthe first of the power sources, and the first line wire in a secondharness is not connected to the electrical output of a second of thepower sources and the second line wire in the second cable harness isconnected to the electrical output of the second of the power sources,whereby in a string of two or more power sources, each connected to acable harness, every other power source is in communication with one ofthe line wires in a string of cable harnesses and the remaining powersources in the string of power sources are in communication with theother of the line wires of the string of cable harnesses.
 14. A powergenerating assembly comprising: a plurality of AC modules for convertingsolar energy to AC electrical power; a junction box in communicationwith said modules; and a line-alternating cable harness assemblyelectrically connecting said junction box to said modules and saidmodules to each other; said cable harness assembly having between alladjacent ones of said modules a line alternating arrangement of linewires, wherein first and second line wires extending from said junctionbox are reversed positionally in said cable harness, such that the firstline wire is in communication with alternating ones of said modules ofthe assembly and the second line wire is in communication with theremainder of the modules of the assembly.
 15. The power generatingassembly in accordance with claim 14, wherein said cable harness isprovided with connector means, selected ones of the connector meanshaving the alternating arrangement of line wires therein in electricalcommunication with contact members at an end thereof; wherein thecontact members are adapted to physically engage and interlock withcomplementary contact members of an opposing connector means to providethe alternating arrangement of line wires; and wherein the contactmembers are configured so as not to physically engage each other if theconnector means are not in complementary engagement with each other;whereby said modules and said cable harness are connectable to eachother in a functioning manner by properly paired connectors, andattempted interconnection of said modules without properly pairedconnectors cannot be accomplished; whereby proper interconnection ofsaid modules and said cable harness is apparent to an installer of theassembly.
 16. An AC module assembly comprising: a first series of ACmodules, each comprising a photovoltaic cell and an inverter forproviding AC current; a second series of AC modules, each comprising aphotovoltaic cell and an inverter for providing AC current; the firstseries of AC modules comprising a first 120 volt AC module buss, and thesecond series of AC modules comprising a second 120 volt AC module buss;said first buss AC modules being interconnected one with another by atleast first and second line wires; the first buss first and second linewires alternating positions from module to module, such that the firstline wire is in active engagement with every other of the first buss ACmodules, and the second line wire is in active engagement with remainingfirst buss AC modules; said second buss AC modules being interconnectedone with another by at least first and second line wires, the secondbuss first and second line wires alternating positions from module tomodule, such that the first line wire is in active engagement with everyother of the second buss AC modules, and the second line wire is inactive engagement with remaining second buss AC modules; a junction boxin electrical communication with said first and second busses; and aservice panel in electrical communication with said junction box. 17.The assembly in accordance with claim 16 wherein a first line wireextends from an end of the first buss to said junction box and a secondline wire extends from an end of the second buss to said junction box.18. The assembly in accordance with claim 17 wherein the first andsecond line wires extend from said junction box to said service panel.19. The line-alternating cable harness in accordance with claim 13,wherein current in the first and second line wires is balanced tomaintain a current limit of one AC power source.
 20. Theline-alternating cable harness in accordance with claim 19, whereinmaximum current on a neutral wire therein is equal to the current limitof one AC power source.
 21. An extension cable harness forinterconnecting two line-alternating cable harness connector means, theextension cable harness having at least two line wires therein, and aneutral wire, the extension cable harness being adapted for connectionof each end thereof to an AC line-alternating cable harness.
 22. A cableharness assembly comprising: an extension cable for interconnectingfirst and second line-alternating cable harnesses, the extension cablehaving at least two line wires and a neutral wire extending therethroughend-to-end; connector means at first and second ends of said extensioncable; said connector means being connectively engageable with an end ofa line-alternating cable harness.
 23. A cable harness for connection toan AC power source, the harness having a plurality of electricallyconductive wires extending therethrough, said wires comprising at leastfirst, second, and third wires separated from each other along thelength thereof and adapted for connection to wires extending from thepower source, wherein said first, second and third wires are changed intheir positions in the cable harness, such that in successive cableharnesses connected to each other and each connected to a discrete oneof the power sources, the first line wire in a first harness isconnected to the electrical output of the first of the power sources,and the second and third line wires are not connected to the electricaloutput of the first of the power sources, and the second line wire in asecond harness is connected to the electrical output of the second ofthe power sources, and the first line wire and third line wire of thesecond harness are not connected to the electrical output of the secondof the power sources, and the third line wire in a third harness isconnected to the electrical output of the third of the power sources,and the first line wire and second line wire of the third harness arenot connected to the electrical output of the third power source;whereby every third power source is connected to a first of the cableharnesses line wires, another third of the power sources is connected toa second of the cable harnesses line wires, and another third of thepower sources is connected to a third of the cable harnesses line wires,and wherein such arrangement continues throughout a string of powersources.